2024 Volume 96 Issue 1 Pages 22-29
For the purpose of further increasing the tensile strength of high-Mn flake graphite cast iron, the effects of graphitization promoting elements (Cu, Sb, Sn) and carbide-stabilizing elements (C, V, Mo) on the chilling tendency and mechanical properties of this cast iron were investigated. The following results were obtained.
1) The addition of Cu to high Mn specimens decreased the chill depth and increased tensile strength (σ). The specimens to which 10% Cu was added had a D-type graphite structure, resulting in chill formation.
2) In the 10% Cu-added specimen, spherical Cu crystals, including MnS crystallized by the binary monotectic reaction of the Fe-C-Cu ternary phase diagram, were crystallized.
3) In high Mn specimens with Sb and Sn additions, σ did not change but the chill depth decreased up to a certain amount of these elements.
4) In the specimens with increased amounts of Sb and Sn, formation of high-concentration phases of Sb and Sn was observed at the eutectic cell boundaries, respectively.
5) In high Mn specimens with Cr and V additions, Chill depth and σ increased and complex carbides containing Cr, V and Mn as a solid solution formed, respectively.
6) In high Mn specimens with Mo addition, the amount of bainite formed increased with increasing Mo addition, and a large increase in σ was observed accordingly.
